Process and apparatus for producing stacks of printed products provided with an additional sheet

ABSTRACT

A method and apparatus for producing stacks of flat objects, such as printed products  28,  wherein the printed products are fed to a preliminary stacking compartment  20,  into which opens the outlet  32  of an arrangement  12  for feeding additional sheets  14.  Located beneath the preliminary stacking compartment is a final compartment  36,  which can be rotated through 180° about a vertical axis of rotation  38  in order to be able to receive from the preliminary stacking compartment  20  sub-stacks  34  which have been rotated in relation to one another. Each sub-stack  34  may be formed on an additional sheet  14  in the preliminary stacking means  18,  as a result of which, in the complete stack  54,  the sub-stacks  34,  each forming a layer, are separated from one another by an additional sheet  14.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a process and to an apparatusfor producing stacks of printed products provided with an additionalsheet. A process and an apparatus of this general type are known, forexample, from CH-A-667 065 and the corresponding U.S. Pat. No.4,565,130.

[0002] In the prior apparatus, a compartment is located beneath apreliminary stacking compartment, in which the printed products, whichare fed from above, are stacked to form preliminary stacks. Thepreliminary stacks, after having been rotated through 180° in each case,are discharged in a state in which they have been rotated in relation toone another. The cover sheets, which are prepared in an arrangement forsupplying loose and printed cover sheets, are introduced into thecompartment by means of a cover-sheet conveyor, with the result that ineach case one printed cover sheet ends up located on the complete stackor beneath the stack which is to be built up in the compartment.

[0003] EP-A-0 968 947 and the corresponding U.S. Pat. No. 6,241,233disclose an arrangement in which, at the same time as a complete stackis ejected out of the compartment, a cover sheet on which the next stackends up located is drawn into the compartment.

[0004] In the case of a process which is known from EP-A0 894 721, andof a corresponding arrangement, the complete stack, comprisingsub-stacks which are set down one upon the other in a state in whichthey have been rotated through 180°, is ejected out of the compartmentin each case with the aid of a slide and fed to a printer and deliverymeans, with the aid of which the stack is provided with a cover sheet.Once again with the aid of a slide, the stack provided with a coversheet is conveyed into a strapping position and strapped.

[0005] A further process and a further arrangement for the protectivewrapping of stacks of printed products are known from WO-A-00/34127.Stacks of printed products which each have an edge distinguished by anincreased thickness are wrapped such that those stack sides in which thedistinguished edges are arranged are completely covered by the wrapperand thus protected to good effect. Since the above mentioned stacks arenot particularly stable in a direction transverse to the distinguishededges, the stacks are ejected, parallel to the distinguished edges, outof a stacking compartment, in which they are formed, directly betweenthe forms of a pair of forks. The stack is pressed between the forks,and the pair of forks, together with the pressed stack, is guidedthrough a curtain of wrapping material. The wrapping material is thenclosed around the pair of forks and around the stack, and the wrappedstack, once the wrapper has been provided, is separated from the pair offorks, by the latter and the stack moving relative to one another, andconveyed away. A pressing fork may be equipped with a movablecompartment for a cover sheet, which is to be supplied in the ejectingposition to a stack, or for applying another flat product. In the caseof the wrapped stack and pair of forks being separated, the compartmentwith the pair of forks is drawn out of the wrapper and the cover sheetremains on the stack.

[0006] EP-A-0 586 802 and the corresponding U.S. Pat. No. 5,370,382disclose an arrangement for forming stacks from folded printed products,in which a preliminary stacking compartment is closed at the bottom bymeans of slide plates and intermediate base elements can be pushed intothe stacking compartment above the slide plates, the fed printedproducts being set down one upon the other on said intermediate baseelements at the beginning of a sub-stack forming operation. As soon as acertain number of printed products have been stacked, the intermediatebase elements are drawn out of the stacking compartment, as a result ofwhich the stacked printed products drop onto the slide plates and thesub-stack is finished by virtue of further printed products being fed.The finished sub-stack is then set down on a raisable and lowerablecompartment base by virtue of the slide plates being moved apart fromone another.

[0007] According to the known processes, and using the knownapparatuses, the recipient specific number of printed products arestacked to form a complete stack and provided with a cover sheet, andthen wrapped in sheet material or tied by means of a band. If a numberof recipients are to be supplied one after the other with a relativelysmall number of printed products, the complete stacks with thecorrespondingly small number of printed products are put together,stacked one upon the other and once again wrapped or bound fortransportation and handling purposes. This requires arrangements forstoring the complete stacks on an intermediate basis, setting them downone upon the other and wrapping or binding them.

[0008] The object of the present invention is thus to improve the knownprocess and the apparatus of the described type such that the additionalarrangements mentioned above can be dispensed with.

SUMMARY OF THE INVENTION

[0009] The above and other objects and advantages of the invention areachieved by the provision of a method and apparatus wherein the printedproducts are serially fed from above into a preliminary stackingcompartment which is bounded at the bottom by a compartment base. Thebase is sequentially closed and opened so that a series of sub-stacksare formed in the preliminary stacking compartment and individuallydropped into a final compartment which is located below the preliminarystacking compartment.

[0010] According to the invention, an additional sheet is arrangedbetween two adjacent sub-stacks. This additional sheet, for separatingsub-stacks located one upon the other, may be a separating sheet, forexample a colored sheet with or without printing. This is achieved, in apreferred manner, by in each case one additional sheet being introducedinto the preliminary stacking compartment in which the printed productsare stacked to form the sub-stacks. Since it is no longer necessary herefor each recipient specific complete stack to be individually wrapped,bound or strapped, a long cycle time is available for packaging, i.e.wrapping, binding or strapping the complete stacks and transporting themaway.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The process according to the invention and the apparatusaccording to the invention will be described in more detail withreference to an exemplary embodiment illustrated in the drawings, inwhich, purely schematically:

[0012]FIG. 1 is a side view elevation view showing an apparatusaccording to the invention for stacking printed products;

[0013]FIG. 2 is a top plan view of the apparatus shown in FIG. 1 with astrapping station following it; and

[0014]FIG. 3 is a schematic side elevation view, showing the apparatuswith a strapping station according to FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015] The apparatus shown in the figures has a stacking arrangement 10,an arrangement 12 for feeding additional sheets 14 and a strappingstation 16, which directly follows the stacking arrangement 10. In theexample shown, the arrangement 12 for feeding the additional sheets 14may be designed, at the same time, for supplying and for printing theadditional sheets 14.

[0016] The stacking arrangement 10 and, in particular, the specificdesign of the final compartment 36 as described below, are disclosed anddescribed in the Swiss patent application 2003 0051/03, filed 14 Jan.2003, and which corresponds to the concurrently filed U.S. applicationentitled “Apparatus for Forming Stacks of Flat Objects”. With respect tothe construction and functioning of the stacking arrangement 10, thereader is expressly referred to these patent applications, which areexpressly incorporated by reference.

[0017] The stacking arrangement 10 has a preliminary stacking means 18,which includes a preliminary stacking compartment 20 which is bounded onall four sides by a compartment base which is composed of means of guidebrackets 22 and at the bottom by a preliminary compartment base which iscomposed of two slide plates 24, which can be moved into the preliminarystacking compartment 20 and moved out of the same. At a distance abovethe slide plates 24, for example fork-like intermediate base elements 26can be moved into the preliminary stacking compartment 20 and moved outof the same again. The construction and the functioning of thispreliminary stacking means 18 and the interaction thereof with arotatable compartment arranged therebeneath are known from EP-A-0 586802 and the corresponding U.S. Pat. No. 5,370,382, which are expresslyincorporated herein by reference.

[0018] The preliminary stacking means 18 can be fed printed products 28,in the present case folded newspapers, in imbricated formation by meansof a feed conveyor 30 designed as a belt conveyor, such that thepreliminary stacking compartment 20 is charged from above.

[0019] Furthermore, the preliminary stacking means 18 is assigned thearrangement 12 for feeding the additional sheets 14 such that the outlet32, which has a pair of conveying rollers for the cover sheets 14, opensinto the side of the preliminary stacking compartment 20 adjacent thebottom thereof, directly above the slide plates 24. In FIG. 1, a printedadditional sheet 14, or so-called cover sheet, rests on the slide plates24 which have been moved into the preliminary stacking compartment 20. Asub-stack 34 comprising a certain number of, in the present case five,printed products 28 is located on the additional sheet. As is indicatedby arrows, the intermediate base elements 26 are moved into thepreliminary stacking compartment 20 in order for the next printedproducts 28 which are fed by means of the feed conveyor 30 to be stackedthereon until the sub-stack 34 has been discharged from the preliminarystacking compartment 20 by virtue of the slide plates 24 being movedout. The slide plates 24 are moved into the preliminary stackingcompartment 20 again and, if appropriate, a new additional sheet 14 forthe next sub-stack 34 can be introduced into the preliminary stackingcompartment 20.

[0020] Beneath the preliminary stacking means 18, the stackingarrangement 10 comprises a final compartment 36 which can be rotatedabout a vertical central axis of rotation 38. The final compartment 36has a compartment base 40 which can be raised and lowered by means of acorresponding drive. After a sub-stack 34 has been received in eachcase, the compartment 36 can be rotated through 180° about the axis ofrotation 38, with the result that the sub-stacks 34 which are set downone upon the other in this compartment have been rotated through 180° ineach case relative to one another.

[0021] In order to reduce the dropping height of the sub-stacks 34 whenthe slide plates 24 are drawn out of the preliminary stackingcompartment 20, and thus to achieve a high stacking quality, thecompartment base 40 in each case is raised until it or the uppermostprinted product of the printed products 28 stacked thereon is located ata small distance beneath the slide plates 24. When the compartment base40 is subsequently lowered, the slide plates 24 are moved into thepreliminary stacking compartment 20 again as soon as the entiresub-stack 34 discharged is located in the final compartment 36.

[0022] In the illustrated embodiment, a complete stack 54 comprisingfive sub-stacks 34 is located in the compartment 36, in each case oneadditional sheet 14 being arranged between the sub-stacks 34. Theseadditional sheets 14 are preferably color separating sheets, possiblywithout any printing. By virtue of the separating sheets, the separationof the sub-stacks 34 can be seen to particularly good effect.

[0023] The compartment 36 is bounded at its four corners by in each caseone vertically extending angle bracket 42, 42′. The angle brackets whichare arranged at the upstream end of the compartment 36, as seen in anejecting direction A, are designated 42 and the angle brackets which arearranged at the downstream end are designated 42′. The angle brackets 42are each fastened on a top and on a bottom endless chain 44, which isguided around corresponding chain wheels 46 at the upstream end and atthe downstream end of the compartment 36, as seen in the ejectingdirection A. Correspondingly, the angle profiles 42′ are each arrangedon a further top and a further bottom chain 48, these being guidedaround further chain wheels 50 which are mounted equiaxially with thechain wheel 46. By means of a drive motor 52, the mutually oppositeangle brackets 42 can be moved synchronously by simultaneous driving ofthe corresponding chains 44, the drive motor 52 being connected via areversing gear mechanism to the chains 44 arranged on the other side ofthe compartment 36. In a corresponding manner, the angle profiles 42′can be driven synchronously by means of a further drive motor (notshown).

[0024] In FIGS. 1 and 2, the angle brackets 42, 42′ have been displaced,by means of the drive motors 52, into a position in which they bound thecompartment 36 such that a gap is present between them and the printedproducts 28 which are to be stacked and those which have already beenstacked, in order to allow raising and lowering by means of thecompartment base 40 without the printed products 28 arranged thereonbeing damaged. However the angle brackets 42, 42′ are located in such aposition that the printed products 28 cannot slide out of thecompartment 36 at all.

[0025] For rotation of the compartment 36, the angle brackets 42, 42′arranged on the two sides of the compartment 36 are moved toward oneanother in each case by means of the drive motors 52 until they buttagainst the stacked printed products 28. This allows very quick rotationof the compartment 36 without there being any risk of printed products28 present in the compartment 36 being shifted out of place or twisted.

[0026] In order to eject a complete stack 54 out of the compartment 36in the ejecting direction A and, at the same time, to feed it to thestrapping station 16, first of all the further angle brackets 42′, orthe latter together with the angle brackets 42, are moved in theejecting direction A, as a result of which, on the one hand, the anglebrackets 42′ move out of the movement path of the complete stack 54,around the associated further chain wheels 50, into the region of theouter, return strand of the further chains 48 and, on the other hand,the angle brackets 42 eject the complete stack 54 from the compartment36. As soon as the ejecting operation has been completed, the anglebrackets 42 and 42′ are displaced back, by means of the drive motors 52,into the position shown in FIGS. 1 and 2 again.

[0027]FIG. 3 shows a complete stack 54, formed in the compartment 36,during-the operation of ejecting it in the ejecting direction A by meansof the angle brackets 42. The angle brackets 42′, which are notillustrated here, are located outside the movement path of the completestack 54, in the region of the return strand corresponding furtherchains 48. A previously formed, ejected complete stack 54 has beenstrapped in the strapping station 16 by means of a band 56 and islocated, in order to be transported away, on a removal conveyor 58designed as a belt conveyor. As is indicated by chain-dotted lines, itis possible, in the strapping station 16, for the complete stack 54 tobe wrapped in a known manner in a sheet material 60 before beingstrapped by a band 56. In this case, the strapping station 16 isdesigned as a wrapping and strapping station or a wrapping station isarranged upstream of the strapping station 16, the complete stack 54,coming from the stacking arrangement 10, being fed first of all to saidwrapping station. Arrangements which are suitable for this purpose areknown from the prior art.

[0028] For the sake of completeness, it should be mentioned that thecompartment base 40 of the final compartment 36 is of cross-shapeddesign, as can be gathered from FIGS. 1 and 2. On the one hand, thismakes it possible to stack printed products 28 with the format which issmaller than the length of the compartment base 40, as measured in theejecting direction A, since the brackets 42 and 42′ can move past thearms of the compartment base 40 which run in the ejecting direction A.At the same time, however, the stability for the stacked printedproducts 28 is ensured by the arms of the compartment base 40 which runat right angles to the ejecting direction A. On the other hand, theoperation of ejecting a complete stack 54 can begin even as thecompartment base 40 is being lowered into its bottom end position.

[0029] A complete stack with the sub-stacks 34, each forming a layer,separated from one another by in each case one additional sheet 14 isformed in the compartment 36 at the point in time which is shown inFIGS. 1 and 2. The complete stack 54 is ejected out of the compartment36 in ejecting direction A and fed to the strapping station 16, for theinitial sub-stack 34 of the next complete stack 54 which is to be formedhas already been formed in the preliminary stacking means 18. Thissub-stack 34 rests on an additional or cover sheet 14, which has beenfed into the preliminary stacking compartment 20 through the outlet 32.The intermediate base elements 26 are moved into the preliminarystacking compartment 20 in order for the next following printed products28 supplied by means of the feed conveyor 30 to be stacked thereon.

[0030] As soon as the complete stack 54 has been ejected out of thecompartment 36, the compartment base 40 is raised to beneath the slideplates 24, whereupon the latter are drawn out of the preliminarystacking compartment 20 and the sub-stack 34 located thereon, with theadditional sheet 14, ends up located on the compartment base 40. Oncethe slide plates 24 have been moved in, a new additional or separatingsheet 14 is fed and the intermediate base elements 26 are then moved outof the preliminary stacking compartment 20 in order to complete thesub-stack 34, located on the additional sheet 14, on the slide plates24. During this time, the compartment 36 is rotated through 180° aboutthe axis of rotation 38 and the compartment base 40 is raised to such anextent that the uppermost product of the sub-stack 34 resting thereon islocated at a small distance beneath the slide plates 24, in order thento receive the next sub-stack when the slide plates 24 are drawn out ofthe preliminary stacking compartment 20. It is also the case here thatthe lowermost sub-stack 34 of the future complete stack 54 has anadditional or cover sheet 14. The sub-stacks 34 are separated from oneanother by means of a separating sheet and have the appropriate numberof printed products 28.

[0031] It is also possible, if a recipient is assigned a large number ofprinted products 28, to arrange, between a cover sheet and a separatingsheet or on a separating sheet, two or more sub-stacks 34 which are notseparated by a further additional sheet 14, but are set down one uponthe other in a state in which they have been offset through 180° inrelation to one another.

[0032] Since the arrangement 12 for feeding and, if appropriate,supplying and printing the additional sheets 14 is assigned to thepreliminary stacking means 18, a high processing capacity is achieved,all the more so if the preliminary stacking means 18 is provided withintermediate base elements 26.

[0033] An arrangement for feeding, supplying and printing cover sheetsmay be designed, for example, such that a paper web drawn off from asupplier roll is printed and a section is severed from the latter ineach case by means of a cutting device during the operation of feedinginto the preliminary stacking compartment. It is, of course, alsoconceivable for additional sheets to be drawn also from a magazine, forthese to be printed, if appropriate, and then introduced into thepreliminary stacking compartment 20. In order to allow a high processingcapacity, each stacking arrangement 10 is preferably assigned adedicated arrangement 12 for feeding and, if appropriate, supplying andprinting the additional sheets 14.

[0034] The feed conveyor 30 may also be a clamp-type transporter, in thecase of which each printed product 28 is retained by a clamp which isfed to the preliminary stacking compartment 20, as is known, forexample, from CH-A-667 065 and the corresponding U.S. Pat. No.4,565,130, and from DE-A-27 52 513 or DE-A-31 30 945.

[0035] For the sake of completeness, it should be mentioned that theoutlet 32 of the arrangement 12 for feeding the additional sheets 14 canalso open out into the preliminary stacking compartment 20 at arelatively large distance above the slide plates 24, so that the coversheets 14 each end up located on the sub-stack 34. However, it ispreferable, as is shown in FIG. 1, for the outlet 32 to be located inthe vicinity of the slide plates 24.

[0036] The final compartment 36 may also be designed as is known fromthe prior art. The compartment 36 need not necessarily be capable ofrotation about its axis.

[0037] It is also possible for complete stacks 54 to be ejected counterto the ejecting direction A. For this purpose, a removal conveyor isarranged on that side of the stacking arrangement 10 which is directedaway from the strapping station 16.

[0038] A rotatable compartment 36 is or is not rotated, as required,prior to a further sub-stack 34 being received. It is thus possible foradditional sheets 14 to be arranged between sub-stacks 34 which areoriented in the same direction.

[0039] All the functions of the apparatus are controlled by a controlmeans (not shown).

1. A method for producing stacks of printed products provided with an additional sheet between sub-stacks thereof, comprising the steps of serially feeding printed products from above into a preliminary stacking compartment which is bounded at the bottom by a compartment base, sequentially closing and opening the compartment base so that a series of sub-stacks are formed in the preliminary stacking compartment and individually dropped into a final compartment which is located below the preliminary stacking compartment, and feeding at least one additional sheet after at least one sub-stack has been formed in the preliminary stacking compartment and before a further sub-stack is dropped upon the one sub-stack in the final compartment so that the additional sheet ends up located between the one sub-stack and the further sub-stack.
 2. The method of claim 1 comprising the further step of rotating the final compartment by about 180° about a central vertical axis between the dropping of the one sub-stack and the further sub-stack thereinto and so that the one and further sub-stacks are disposed in a relationship rotated about 180° with respect to each other.
 3. The method of claim 1 wherein the feeding step comprises feeding the additional sheet into the preliminary stacking compartment at a location above the compartment base so that the further sub-stack is formed upon the additional sheet.
 4. The method of claim 1 wherein the additional sheet is fed after the one sub-stack has been formed and dropped into the final compartment and before the further sub-stack has been formed.
 5. The method of claim 1 comprising the further step of feeding another additional sheet into the preliminary stacking compartment before the one sub-stack is formed so that the one sub-stack ends up located on the another additional sheet.
 6. An apparatus for producing stacks of printed products provided with an additional sheet between sub-stacks thereof, comprising a preliminary stacking compartment which can be serially supplied with printed products from above and which is bounded at the bottom by a compartment base which is mounted for movement between a closed position wherein the fed products may be stacked to form a sub-stack, and a withdrawn position, a final compartment positioned below the preliminary stacking compartment into which the sub-stacks are sequentially dropped when the compartment base of the preliminary stacking compartment is moved from its closed position to its withdrawn position, to form a complete stack, and means for feeding an additional sheet after at least one sub-stack has been formed and before a further sub-stack is dropped onto the already formed sub-stack in the final compartment, and such that the additional sheet ends up located between these two sub-stacks in the final compartment.
 7. The apparatus of claim 6 wherein the final compartment is mounted for rotation about a central vertical axis and the apparatus further comprises a rotation drive for selectively rotating the final compartment about said axis by about 180° so that sub-stacks can be dropped one upon another in a relationship rotated about 180° in relation to one another.
 8. The apparatus of claim 6 wherein the means for feeding an additional sheet has an outlet which is positioned to deliver the sheets into the preliminary stacking compartment.
 9. The apparatus of claim 8 wherein the outlet is positioned to deliver the sheets into the preliminary stacking compartment at a location immediately above the compartment base.
 10. The apparatus of claim 9 wherein the portion of the preliminary stacking compartment above the outlet includes an intermediate base which is mounted for movement into and out of the preliminary stacking chamber and on which the printed products may be stacked until the relevant additional sheet is introduced into the preliminary stacking chamber.
 11. The apparatus of claim 9 wherein the means for feeding an additional sheet is programmed to feed an additional sheet before the one sub-stack is formed.
 12. The apparatus of claim 6 wherein the apparatus further comprises a strapping and/or wrapping station which is positioned to receive complete stacks from the final compartment. 